Coffee maker



May 9, 1950 F. P. STROTHER 2,507,283

coFFEE MAKER original Filed Aug.' 1, 1942 Patented May 9, 1950 UNITED STATES OFFICE (BUFFER MAKER Fred P. Strother, Minneapolis, Minn., assignor to Sears, Roebuck and C0., Chicago, lll., a corporation of New York 2 Claims.

This is a division of my Patent No. 2,386,278, granted October 9, 1945, entitled Coiee maker.

An important object of the invention is to pr vide a coffee maker having a novel construction and arrangement of parts.

A further object is to provide a novel releasable filter-locking assembly.

lt is also an object to provide novel filter-removing means.

Further objects and advantages of my invention will appear as the description proceeds.

The invention will be understood better upon reference to the following description and the accompanying drawing, in which:

Fig. 1 is a vertical sectional View of an illustrative coffee maker built in accordance with the invention, taken as indicated by the line l-I in Fig. 2;

Fig. 2 is a plan view taken as indicated by the line 2MB in Fig. 1;

Fig. 3 is an enlarged fragmentary sectional view taken as indicated by the line 3--3 in Fig. 2;

Fig. 4 is a sectional plan view taken as indicated by the line 4-4 in Fig. 3; l

Fig. 5 is an enlarged fragmentary plan sectional view taken as indicated by the line -5-5 in Fig. 6;

Fig. 6 is a fragmentary vertical sectional view taken as indicated by the line 6--6 in Fig. 5.

Referring now more particularly to the drawing, there is shown for illustrative purposes a lower pot iii having a suitable preferably heatinsulating handle Il and pouring spout lla, and a base I2 with four or any other suitable number of heat-insulating feet I4 and a large mouth I5 embracing a rubber or other suitable gasket ring I6 by means of which an upper pot I8 is supported. The lower pot l0 has a heat conducting plate iioor I9 soldered or brazed as at 2E) or otherwise suitably connected to the side wall 22 of said lower pot, and spaced therebelow a disc or pressure plate 23 spot-welded as at 24 or otherwise suitably connected to said side wall. The resulting space 26 is occupied by an electric resistance heating unit 21 such as a wire 28 wound about and between upper and lower mica sheets 39 suitably held in assembly with the pot I6, said sheets being portions of a wrapper or enu velope if desired and insulated electrically from said pot, etc.

Secured to and under the disc 23 as by screws 32 (Figs. 5 and 6) is a supporting plate 33 to which a toggle lever 34 is pivoted as at 36, said lever being urged selectively toward one or the other of two stops 31 and 38 by a spring 4o anchored at 4I to the lever at one side of the pivot and at 62 to the plate 33 at the opposite side o1' the pivot.

The lever 3d has depending ears 44 and 45 to which nuts 46 may be fastened or welded as at 4l to receive screws 48 and 50, respectively, adapted to be adjusted toward and away from each other. Disposed in lost motion relation to and between the screws 48 and 50 is the free end 5l of a thermostat bimetal 52 Whose other end 5i is anchored as at -55 by a screw or rivet between the fork arms 56 of a heat transferring stud 58 depending from the hot plate I9 through an opening 5d in the disc 23. The ear 45 has an extension 6l carrying a porcelain or other insulation pin 62 engageable with the movable spring arm 63 of a switch B5 to close the same, the switch being however normally open. The arm 63 has a contact 66 engageable with a contact 6l on a second spring arm 69 of the switch, the other ends of said arms being anchored as at 10 between and separated by suitable insulating blocks il held between a plate 13 and a bracket 14 carried by the plate 33. A nut 16 Welded or fastened as at il or otherwise secured adjacent the free end 5l of the bimetal 52 receives a screw it having a porcelain or other insulating end engageable with the switch arm 53 to close the switch. One of the switch arms 63 and 69 is wired as at 8l to one terminal 82 of the heating element 2i! and the other switch arm and the other terminal 64 of the heating element 28 are wired as at to prongs 86 suitably secured to and insulated from the base housing I2 and shielded by a shell or socket 8l (Fig. 1).

The upper pet i8 has a floor 90 open centrally as at 9i and has brazed as at 92 or otherwise suitably secured thereat a tube 94 adapted to terminate short of the floor I9 of the lower pot. A rod 96 is provided, having a stem 91 adapted to be received in the tube 94 and having a handle QS arranged to be grasped and manipulated conveniently through the mouth |60 of the upper pot. A ferrule lo! about the stem 91 and having a dished spring spider or other suitable perforated member i9? welded or otherwise fastened thereto is held against longitudinal displacement by abutments 65 which may be upset from the stem. A pressure plate 06 also in the form of a spider or other suitable perforated member may be integral with or suitably fastened to a sleeve i833 adapted to be telescopically assembled with the ferrule |01 and to be releasably held in a predetermined relation with the Spring member m2 under tension of the latter by means of a snap spring or pawl |09 releasably received in with the bore of the spider |08 and its sleeve |08. l.

Secured as at IIG to the lower end III of the stem 9'I is a sleeve II carrying a spring` pawl I 20 cooperative with teeth IZI on a ratchet stud |22 centrally secured as at |24 to and projecting up from the floor I9 of the lower pot I 0'. The lower end of the tube IIS is Ipreferably flared or belled as at |25 and the top IE6' of the' stud is preferably rounded to guide the tube over and about the stud as the tube descends, the top ofv the stud also readily camming the pawl I 28 aside as the latter descends. The stud is flattened at one or opposite sides I 29 to afford in effect a plurality of bayonet joint adjustments with the pawl |20. Thus, as the pa-wl |28- descends it may snap over the teeth- I2! or it may be disposed as shown in dotted lines in Fig. 4, 90 from the position shown in full lines, until the lower spider |06 is seated. in the depression I l2, andthen, if in the dotted line position, itis turned 90 to engage the appropriate ratchet tooth whereby to releasably lock the filter assembly in operative position and also releasably lock the twoY pots together. The upper spider |02 is sufficiently resilient to enable the user to press it dow-n until the pawl engages a tooth low enough to insure against any looseness or rattling of parts. Rotation of the handle 98 9G from the full line position will release the pawl and allow the assembly to be removed. The inside diameter of the lower spider |86, sleeve |68 and lter are such as to enable them to slip past the spring |28 and tube I8, whereby an old lter may be readily replaced by a new one. The entire lter ensemble is re movable and insertable through the mouth of the upper pot I8.

As seen in Fig, 5, the thermostat 52 moves in the direction C as it cools and in the direction H as it heats. Accordingly, when the device is cold: the thermostat button 8B is in engagement with the switch arm Ge and holds said arm against its spring resistance (and possibly also the spring resista-nce of the arm 88) in the position shown, wherein the contacts S8 and 6?. are engaged and hence the switch B is closed. At suchtime, also, the toggle lever 6I is on the near si'de of dead center, i. e., the side on which the stop pin 38 is disposed, where the lever is held by the toggle spring 83, which accordingly holds the button 82 against the switch arm 63 in switch-closing position.

In making coifee with this apparatus, the plug socket IrSl', connected to a wall socket (not iown), is plugged in at 8l to the prongs 85, projecting from the base I2, to supply electric energy to the heating element 28. As the temperature of the hot plate I'SI rises, the water in the lower. pot lo steams. At the same time, the binietal 52, becoming warm, moves inthe direction H, and may become free of the switch arm E3 but does not move sufficiently to withdraw the button 62 sulnciently to allow the arm 63 to spring open. The steam ultimately drives the liquid upV the tube 80, and thereafter, due to the reduction of water to be heated by the hot plate I9; the temperature of the plate rises rapidly,

as does also that of the bimetal 52, which engages the pin 48 and promptly trips the lever 34 past dead center into engagement with the stop 31, the switch arm 63 at such time springing to openswitchv position.

After the ground coffee over the lter II3 in the upper chamber or pot I8 is flooded, the vacuum caused by the condensing steam in the lower pot causes the coffee liquor to descend to the lower compartment or pot I0 and form coffee suitable for drinking. After the opening of the switch. G5 the hot plate I9 and consequently the thermostat 52 starts to cool. The calibration is such that when the temperature ofthe coffee in the lower compartment I0 has dropped to approximately F., for example, the adjustable porcelain-tipped point 88 has engaged the switch arm 63 and moved it to switch-closing position, without however having moved the lever 34 at all or at any rate sufficiently to trip the lever past dead center. The temperature of the coffee accordingly again rises, but when it has reached approximately F., for example, the bimeta'l E32V has again retrogressed to a point enabling the switch arm 63y to spring open. The consequent cooling restarts a series of these cycles whereby the temperature. of the coffee may bev maintained indefinitely at a proper temperature between say 180 F. andA 185 F. for serving.

When the socket plug I3I is withdrawn from the coffee maker, thereby disconnecting the latter from the line, the bimetal 52 cools and moves into engagement with the point 58 on the lever 34v which, at a temperature of approximately 125 F., for example, trips past dead center and forces the switch arm 63 into switch-closing posi'- tion, as shown in Fig. 5, ready for repeatingv the above-explained operation upon reconnection with the line for making another pot of coffee and retaining it at the desired temperature for serving.

It is evident from theforegoing that with my construction the human element is eliminated sinceV there is nothing to preset in order to place the appliance in operation.

The' parts maybe readily calibrated or constructed to open and close the switch at any desired temperatures. All calibrations may be made at the factory and thereupon all screws may be soldered or brazed in place.

The feet I4 may be mounted on a base plate |35 which may be attached as by screws |36 to lugs or other means |33 spot-welded as at |39 or otherwise suitably attached to the heating element housing.

Theilter unit is` assembled by slipping a filter cloth andV thereafter theY lower spider |06 with its sleeve |88 past the pawl` |20 until the spring Ii09 snaps into the groove I-IG, thereby resiliently clamping the filter cloth against the spring spider Ill-2. To removethe cloth this procedure is reversed, the spring I ll4 readily snapping out of thegroove IIIly upon being pulled down by the user.

Various' modifications coming within the spirit of my invention may suggest themselves to those skilled inthe art, and hence I do not wish to be limited to the specic form shown or uses mentioned, except to the extent indicated in the appended claims, which are to be interpreted as broadly as the State of the art will permit.

I claim:y

1. In an apparatus for brewing coffee, a bottom containing vessel shaped with a constricted mouth opening uppermost thereof, a top containing vessel having a base portion shaped to be received in snug-fitting nested relation within said constricted mouth opening of said bottom vessel and having a uid permeable partition constituting a bottom wall thereof with a central opening in said bottom Wall, in combination with a device for releasably securing together said top and bottom vessels comprising a vertical stud anchored in the floor of said bottom vessel, said stud having certain of its vertical element surfaces smooth and other of its vertical element surfaces serrated with ratchet teeth formations of which the perpendicular tooth edges are lowermost, and a coupling rod rotatably journaled in said central hole of said permeable partition bent at its upper end, whereby to afford manipulation, and provided at its lower end with an opening for admitting said anchored stud, and carrying a springable latching claw that may be yieldably ratcheted downwardly over the serrations of said stud and in so doing have biting engagement with its said lowermost edges, and whereby upon being rotated by said manipulation bent portion to be disposed free of engagement with said serrations for affording freedom for disassembly to said bottom and top vessels.

2. The combination set forth in claim 1 in which said coupling rod is provided at its lowermost extremity with a coupling sleeve whose opening is shaped with a flared mouth to assist in guiding said stud and in which the cross section of said opening conforms with that of said stud in order to establish predetermined alignments therebetween.

FRED P. STROTHER.

REFERENCES CITEDl The following references are of record in the le of this patent:

UNITED STATES PATENTS 

